1. Field of the Invention
The present invention relates to a method of forming patterned conductor lines (i.e. a conductor pattern) of an electronic device, such as a semiconductor device, a magnetic bubble memory, a thin film hybrid integrated circuit or a thin film magnetic head, by using an electron-beam lithography technique.
2. Description of the Prior Art
The electron-beam lithography technique was researched and developed for the microfabrication of denser semiconductor devices (such as integrated circuits (IC's) and large-scale integrated circuits (LSI's)). Negative electron-sensitive resist and positive electron-sensitive resist are used as the medium for pattern resolution. In general, negative resist is characterized by high sensitivity, while positive resist is characterized by high resolution. In actual microfabrication process, since conductor lines are formed on an IC or LSI chip by etching a relatively large portion of the conductive layer, negative resist is most often used for formation of conductor lines. On the other hand, since through hole are formed in an insulating layer of an IC or LSI chip by etching a small portion of the insulating layer, positive resist is most often used for formation of through holes.
Electron-sensitive resist is disclosed in publications such as M. Hatzakis, "Recent Developments in Electron-Resist Evaluation Techniques", Journal of Vacuum Science Technology, Volume 12 (1975), No. 6, page 1276 to 1279, and J.Shimada, "Kinds and Properties of Resist for Electron-Beam Exposure", Electronic Parts and Material, Volume 18 (1979), No. 10, page 28 to 34.